Yeah. Sure. But on the flipside: a javascript library providing 10+ years of back- and forward-compatability with every different browser under the sun? Maintained by one guy? There's no way that's not a massively bloated piece of software that probably ought to be replaced anyway.

The market abhors a vacuum. Presumably no one stepped in because it wasn't broken enough yet, and there are competitors or replacements, as he mentioned in the post.

The other part of me wonders how much of a requirement continuing cutting-edge development is for this library. That just entails back-porting new JS features to engines that don't support them yet. I can see, like, back-porting common JS features that have been around for like ten years, which have worked their way into common usage, back to IE8. But for the new stuff ECMAScript is adding, the only thing is that it would be adding native support for features that are almost certainly covered in other packages. And if you have to use a library to ensure those features work anyway, it's the same thing.